


Baby Mine

by justanothersong



Category: Captain America (Movies), Marvel Cinematic Universe, The Avengers (Marvel Movies)
Genre: Age Regression/De-Aging, Alternate Universe, Babies, F/M, Reader-Insert
Language: English
Status: Completed
Published: 2017-01-23
Updated: 2017-01-23
Packaged: 2018-09-19 09:45:58
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,946
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/9433970
Author URL: https://archiveofourown.org/users/justanothersong/pseuds/justanothersong
Summary: “Not the time, Natasha,” Steve gritted out. “Why do you have a baby? And why are you bringing her here, to me?”Natasha clicked her tongue again. “Really, Steve?” she asked, shaking her head, teasing tone still evident in her voice. “Are you going to tell me that you don’t recognize her?”





	

It was well known among his team that Steve Rogers was not much one for following orders that he disagreed with, so when it was decided that he should not accompany the others on their latest mission, it shocked them all when he frowned a moment before nodding and say, “Yes, that’s probably best.”

Steve may have been a little bit reckless, but he was far from stupid; he understood that this particular mission could be especially dangerous for him. A small terrorist cell with a chip on its shoulder against earth’s mightiest heroes had turned towards bioengineering a virus to take them on directly, and word had it they had succeeded; whatever the product of their labor had been, its intent, so far as the intel had been garnered, was either to revert those exposed to the mental capacity of toddlers or, perhaps less likely, to physically transform them to the age.

As far as Steve was concerned, there were some risks even he deemed not worth taking. His early life had been hell, and small as the possibility was that something had been created that could physically transform him, he knew the risk to him personally was too great.

He felt terribly guilty, staying back at the compound while everyone else went to work, but you had all agreed it was best he stayed behind. An inconvenience for some could be all but deadly for the Captain, and no one wanted to see that happen.

 

Steve moped around, unsure of what to do with himself. He couldn’t concentrate to read, constantly glancing at his phone in search of some sign that you were all doing well without him. He tried watching television, but his mind kept drifting, and he’d drum his fingers impatiently on the arm of the couch in the common room, trying to make the hours pass a little faster.

When he finally heard the approach of a helicopter, he jumped out of his seat.

“Oh thank Christ,” he muttered, peering out the windows to get a look at what kind of shape everyone was in. He was surprised to see that the chopper blades kept spinning, even as Natasha jumped out, cradling a small bundle to her chest and running for the compound. He was just heading out of the common room to meet her when she burst through the door.

“Natasha, what’s going on?” Steve demanded, voice quickly taking on the authoritative tenor he used in the field. “Where is everyone else? Why is the chopper still running?”

Natasha gave him a tight smile. “Just stopping back to deliver a package to you, Cap,” she told him, thrusting the bundle into his arms. “Clint’s keeping her running, I have to get back before all hell breaks loose.”

“What?” Steve asked , frowning down at whatever she had pushed into his arms. “Nat, what the hell…?”

He stopped cold when Natasha’s special delivery began to cry.

Almost at the door, Natasha swore under her breath and trotted back, shaking her head. “God damn it, Steve, I just got her back to sleep.”

Steve gaped, unable to form words as Natasha gently retrieved the crying toddler from his arms, dropping the soft grey blanket she had been wrapped in onto the floor in the process. The little girl couldn’t be more than a year or so, and was wearing only what looked like one of Clint’s sleeveless shirts, sobbing with everything she had, face red and frightened.

Natasha clicked her tongue and tutted at the baby. “No no, malyshka, you’re alright,” she said, voice pitching just an octave or two upward as she spoke to the child. She held the baby close and bounced her in place, cooing and speaking softly to try and calm her. “We’re fine, we’re fine,” she intoned. “Steve here is going to take care of you. You’ll love him, won’t she Steve?”

Steve had seemingly lost the capacity for speech, only stared, wide-eyed and completely stunned.

The baby had calmed a little, still sniffling and whining but listening intently to Natasha, and had even chanced a smile. When Natasha turned the baby in her arms to look at him, she had even giggled before burying her face against Natasha’s chest.

“Oh, someone’s flirting with you Steve,” Natasha teased.

“Natasha, what the hell…?” he finally spat out.

She arched one fine red eyebrow at him. “Language, Steven? Little ears present,” she said, and smirked.

“Not the time, Natasha,” Steve gritted out. “Why do you have a baby? And why are you bringing her here, to me?”

Natasha clicked her tongue again. “Really, Steve?” she asked, shaking her head, teasing tone still evident in her voice. “Are you going to tell me that you don’t recognize her?”

The baby had looked up again, and was playing with a loose strand of Natasha’s hair. Steve peered in closely, frowning a little before his blue eyes suddenly shot wide open in shock.

“It can’t… it can’t be…!” he said.

Natasha laughed. “It can, and it is,” she responded, and handed the child over to him. “It was in some sort of liquid, they were spraying it with a pressure washer. Deflected off of Tony and she took the full brunt of it.”

“Oh my god,” Steve muttered, staring at the baby in awe. He held her easily, unconsciously bouncing on his heels in mimicry of the motions that Natasha had been making only moments before. “This is… I mean, it’s amazing, but it’s… it’s…”

“Bizarre?” Natasha offered, crossing her arms over her chest. “Astounding? Mildly terrifying? Or maybe all of the above? Anyway, she’s your responsibility for now. I have to get back, we have a prepubescent Starkling running around the small base we took on and we need to rein him in while we look for the cure, or antidote.”

“Natasha, I can’t look after her like this!” Steve said, voice edging into panic as he took a step towards the redhead.

She held up her hands. “Sorry, Cap. Clint’s got the bird still running for me, I’ve got to go. You need to get that baby fed and changed, and she probably needs a bath. We won’t be too long, I’m sure.” 

She was already halfway out the door, and Steve tried to hurry after her, stopping in his tracks when the baby started to whine.

“Natasha!” he shouted, and heard her laughter in response. 

“C’mon Steve, you should be the one taking care of her,” she called back. “After all, she’s you’re girlfriend!”

 

‘Girlfriend’ was a little bit of an overstatement, you would have told Natasha, if your recently regressed mind had given you any capability to do so. You and Steve had been on all of three dates, and while they were absolutely wonderful, and his goodnight kisses had sent your heart flying, it was a little early on to be using titles.

Even if you had known each other for going on three years, since you had first been recruited to join the Avengers team, and flirting a little cautiously back and forth for at least two.

It was nice. It might have been going slowly, but it felt perfect. It had been hard to make a move, trying to bridge the gap between coworkers to friends to something more, but the timing had always been off until recently and finally, finally you had both gotten on the same page and you felt like there was a real future there.

Or, at least you would have, if you weren’t so busy gnawing on Steve’s thumb.

“What am I going to do with you?” Steve whispered, more to himself than to you. You made a garbled coo in response and continued your work of gumming at his thumb; you seemed only to have a single tooth or two, only half emerged, and neither enough to do any real damage.

“I knew you must’ve been a cute baby,” Steve said, smiling gently when you grinned up at him, drooling around his thumb. You pulled it out of your mouth and grabbed at the rest of his hand with spit-dampened fingers, seemingly transfixed with the patterns of his fingerprints and the curves of his cuticles.

“Yeah, you’re a beautiful little girl, aren’t you?” Steve asked, tipping your chin up to look at your round little toddler face. You told him something sternly in babytalk, and went back to exploring his hand, and Steve couldn’t help but laugh.

“Come on, darlin’,” he said with a sigh, rising from the couch with you in his arms. “Let’s find you something to eat, okay?”

 

Of course, there was no high-chair anywhere in the compound, and after testing a few possibilities, Steve finally settled on stacking two couch cushions atop one another on a kitchen chair and securing you in place with two winter scarves.

It certainly wouldn’t pass any child services inspections, but it would have to do.

He gave you a spoon to bang on the table while he searched the kitchen for something he could give you to eat.

“I’m not really sure what you can have,” he confessed, keeping you in his peripheral vision as he scoured the refrigerator and kitchen cabinets. “It’s not like I’ve had much experience around babies. I’m not even sure how old you are!”

You agreed with a loud bang of your spoon and a hearty cry of “Naaaaa!”

Steve couldn’t help but smile at your exclamation. “And it’s not like you can give me pointers,” he added, and you continued your percussive symphony against the tabletop.

“How about…” Steve began, opening a tin-foil covered container in the refrigerator. “Some leftover mashed potatoes and… applesauce!” he added, spying the half-filled jar in the fridge door. He turned around and held them aloft, as if asking your opinion.

You simply laughed and banged your spoon.

Actually feeding you became something of an adventure. The first time you blew a raspberry with a mouthful of potatoes, Steve made the mistake of laughing, even as the sticky mess was sprayed all over his chest. After that, you repeated the action with nearly every other mouthful.

“I finally get it,” Steve said with a laugh, wiping a fresh spray of applesauce off of his cheek. “Ma used to say I was a messy eater, too. Got more on me than in me. You, little girl, are even worse.”

You responded with a loud “Mmmmuhmuhmuhmuhmuh,” and smacked your lips, which Steve had learned meant that you wanted more. Thankfully, you decided to actually eat the new bite of applesauce, barely half of it dribbling down your chin.

“I think,” Steve said, lifting a spoon to your lips with another mouthful, “You’re really going to need that bath after all of this.”

You responded by blowing another wet, applesaucy raspberry.

 

Steve didn’t feel too guilty about slipping into Natasha’s quarters to borrow some soap and shampoo to give you a back, since she did all but abandon him with an infant he had no idea how to care for. He thought he was maybe doing a decent job of winging it, but still felt a little strange giving you a bath in his tub, using the simple bar soap and tea tree oil shampoo he used. So he poked through the bottles in Natasha’s bathroom cabinet until he came up with a lavender body wash and honey-scented shampoo.

“What do you think?” he asked, balancing you in one arm as he held the two bottles aloft by their caps in one hand.

You responded by completely ignoring the question and reaching to pull at his earlobe, which he decided to take as a yes. It turned out for the best, as you had really needed the bath after dinner and having messed in the tied-off shirt you had been dressed in. 

“I sure hope you don’t remember everything when this is all over,” Steve said with a sigh, breaking into an indulgent smile as you slapped the water with both hands and laughed. It wasn’t deep enough to splash beyond the rim of the tub where he knelt, washcloth in hand and a plastic cup stolen from the kitchen to help with washing your hair sitting on the tile floor beside him. 

You only babbled back at him and tried to eat some of the bubbles, making an angry nose and splashing the water a little harder when he pulled your tiny hand from your mouth. He couldn’t help but laugh at the annoyed expression that crossed your face, as it was nearly identical to the one you’d wear as an adult and something would get on your nerves.

You cried a little when he washed your hair, not like the way he tipped you forward with his wide palm braced against your belly to rinse your hair, but calmed soon enough as he wrapped you in a warm fluffy towel.

“I don’t really have anything for you to wear,” Steve apologized, carrying you into his dimly lit bedroom. “Certainly can’t put you back in what you had on.” He had left Clint’s soiled shirt on the bathroom floor, to be dealt with in the morning; he was finding himself feeling the same kind of bone-deep fatigue he’d previously only encountered after returning home from a trying mission, and inwardly wondered how his mother had managed when it was just the two of them, all on their own.

He frowned a long moment, glancing around his room, before make a decision and pulling open a dresser drawer with his free hand. You had grown sleepy from the lavender in your bath and you’d snuggled into the towel and into his shoulder, awake but watching with heavy-lidded eyes as he pulled out a t-shirt.

“I think this will have to do,” Steve said softly, smiling down at you. He laid your little body down on his bed and dried you as best he could while you wiggled around. He quickly found that you were ticklish on your sides and made you giggle and squirm until you were heaving great belly laughs. When you yawned, deep and long, Steve smiled gently, knowing it was time for you to sleep. He dried your hair a little more and pulled it into two loose pigtails with a pair of hair-ties that Bucky had left laying around, and pulled his t-shirt over your head.

You gave another quiet giggle when he called out a soft “Peekaboo!” as your head slipped through the collar, but settled back against the mattress and stared up at him with half-lidded eyes.

“Where are we going to put you to bed, sweetheart,” Steve pondered aloud, glancing around the room in hopes that inspiration would strike. It wasn’t as though there would be a crib or a cradle on hand, after all.

After a long moment of puzzling over his options, Steve’s eyes lit upon his dresser drawer, still half-hanging open from his retrieval of his shirt only moments before. Biting his lip, he stared another long moment before he sighed.

“I guess it will have to do,” he muttered, and stood to pull the drawer completely from his dresser, dumping his clothes out onto the floor and returning to the bed just in time to grab you at the waist as you tried to squirm away.

“And here I thought you were sleepy,” he said with a short laugh, and you gave a sleepy smile and lazy giggle in return, snuggling against his chest. Back to maneuvering one-handed, Steve somehow managed to turn the dresser drawer into a passable cradle for the night, with a pillow and a few towels to create the illusion of a comfortable bed. 

You went down easily enough, clearly tired out from your ordeal, and Steve yawned himself. He stripped off his shirt, still damp from your bath and sticky with applesauce and bits of potato, and tossed it into the corner, too tired to care about finding a hamper. He kicked off his jeans and grabbed a clean t-shirt from the pile he had dumped on the floor, before sparing you one last glance and slipping into his bed. His head had just hit the pillow when you began to fuss.

It was just a few quiet whimpers and first, and the sound of your little body shuffling against the fabric of the towels and pillow. You’d make a nose and then pause, and Steve would wait, hoping you were just settling yourself for the night, but without fail, you’d begin again in a minute or so. It drew into longer whimpers until you began to really cry and Steve got out of bed, peering down at you in your little makeshift cradle on the floor, sitting up with a red, tearstained face, holding your arms up to him.

In an instant, Steve had scooped you up, holding you close and bouncing as he whispered soothing things to you, begging you to calm down and promising you that you were safe.

“C’mon, sweet pea, it’s me, you’re old pal,” he said softly. “I’d never let anything bad happen to you, would I?” He smiled down at you and you seemed to calm, but the moment he moved to lay you back down in your little cradle, you let out a wail.

“Oh, no, no, that’s okay, baby, that’s okay,” Steve said, immediately straightening up. “You don’t have to go back in there. C’mon, you can lay down with me, okay?”

He slipped back between his sheets, holding you close, and you snuggled your little body into his chest, sighing contentedly. He folded one arm beneath his head, watching the night sky out the window while absently stroking a hand down your back, feeling your breathing becoming slow and even. Not knowing many lullabies, Steve struggled to think of something appropriate, and began to hum the only song he could think of, a tune he vaguely remembered from an old Disney picture about a little elephant.

When he ran out of bars and chords to hum, Steve sighed.

“What are we going to do with you?” he asked into the quiet of his bedroom. It was late, and he was growing worried; surely the team would be back by now, or would have at least contacted him, had they found a cure to this madness. His phone sat dark and silent on his nightstand; it hadn’t made a noise all evening.

“I won’t let them take you away,” Steve reasoned aloud. “This is my fault. I should have been there. If we’d had another body on the ground, we could have stopped this… it was meant for me, anyway. Maybe if I hadn’t been so concerned with myself, I could’ve been there to stop this from happening to you.”

He sighed again. “I’ll take care of you, if there’s nothing we can do. Raise you myself. I bet Tony could make it legal, make it look like you were your own daughter on paper. We can say that we lost you on a mission, and I’ll be raising your daughter. Our daughter.

“They’d maybe want to shift you off somewhere, adopt you out, but I won’t let them,” Steve told you, voice soft but fierce in his decision. “I’ll take care of you, retire from all this if I have to. Keep you safe. Then, maybe, one day when you’re grown, I’ll tell you about the woman you were. But I’ll tell you about it as though it were your mother. So you’d know how amazing you were -- and how much I loved you.”

You were sleeping now, and Steve shifted carefully, rolling onto his side and placed you on the bed beside him, rolling blankets and moving pillows around so that you couldn’t fall to the ground in your sleep. He kissed your forehead with a soft, sorrowed sigh, and leaned back against the mattress, watching the gentle rise and fall of your chest until his eyes felt heavy and he drifted off to sleep.

He dreamed that night about a little girl who looked just like you, but had his eyes.

 

It was a little after three in the morning when you woke, your body wracked with such astonishing pain that you couldn’t even cry out, your voice stolen and choked back by the utter torture you were feeling. It was as though something was pulling at you, every inch of you, tearing and stretching and ripping your body in every direction. You tensed and curled in on yourself, the spasms coming hard and fast until you shifted and fell off the bed with a pronounced clunk.

Steve was up like a shot, calling your name out into the darkness in a worried tone of voice, scrambling to turn on the bedside lamp, terrified that he didn’t hear you crying.

“I’m okay,” you called, the pain fading to a strangely relaxed feeling in your muscles, coupled with only a bit of soreness. You pulled yourself back up onto the bed, only dimly aware that you were dressed only in one of Steve’s t-shirts. “Sorry, I didn’t mean to wake-”

Your words broke off when you felt yourself suddenly enveloped in the tightest hug you’d ever felt, Steve’s strong arms wrapped around you and his face buried in the crook of your neck, repeating over and over again, “Oh my god, you’re back, you’re back…”

You were a little surprised when he kissed you, so elated as he was to see you back to your old self again, but you kissed him back eagerly, glad to be in your adult body again and glad to see him so happy at your return. It wasn’t long before it turned heated and Steve was pulling away from you gently, drawing out a frown on your features.

“Steve?” you asked quietly, fearing you had crossed some line. After all, as long as you had known each other, you’d really only had three dates and done nothing more than share a few wonderful goodnight kisses.

“It’s not that I don’t want…” he started, clearly flustered. “God, believe me, I do, I want you so badly I could… but it just feels off… I mean, it was only a few hours ago I was singing you to sleep.”

You couldn’t help but laugh. “I remember,” you told him quietly. “Mind if I still camp out here, though? I promise, I’ll keep my hands to myself.”

“You’re crazy if you think I’d ever be kickin’ you outta my bed, darlin’,” Steve told you, and you resettled the bedclothes and let him draw you into his embrace, closing your eyes and smiling to know that you were still wanted, after everything that had happened.

“You remember?” Steve asked after a long quiet moment.

You smiled against his chest. “For what it’s worth, I think you’d make a great dad,” you remarked.

Steve laughed, the vibrations of his chuckle rumbling through his chest. “Well, I kept you fed and clothed, anyway, so it’s a start.”

You laughed along with him, letting the moment pass before speaking up ever so quietly to say, “You said you loved me.”

“I did,” he agreed, arms tightening around you. “And I’d never lie to you, no matter how old you were lookin’ at the time.”

“Good,” you said with a sleepy hum, as you began to drift off to sleep. “Glad to know it’s not just me.”

Steve pressed his lips to the top of your head, breathing in the warm scent of honey shampoo. “Goodnight, sweetheart,” he said, voice barely above a whisper. “I love you.”

**Author's Note:**

> Title taken from the song Steve hums, from Dumbo :)


End file.
